Vehicle accessory control interface having capactive touch switches

ABSTRACT

A system for enabling an operator to control a vehicle accessory includes a control interface and a processor. The control interface has a display surface and a touch area defined by an electrically conductive layer adjacent the display surface. The conductive layer capacitively couples to an electrically conductive object upon the object touching or being in proximity with the touch area while the conductive layer is driven with an electrical charge. The processor drives the conductive layer with the electrical charge, detects the capacitive coupling of the conductive layer to the object upon the object touching or being in proximity with the touch area while the conductive layer is driven, generates a signal indicative of the object touching or being in proximity with the touch area upon detecting the capacitive coupling of the conductive layer to the object, and provides the signal to the accessory for controlling the accessory accordingly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a control interface of a vehicle inwhich the control interface has input controls for enabling an occupantof the vehicle to control an accessory of the vehicle.

2. Background Art

A vehicle such as an automobile has one or more control interfaces forenabling an occupant of the vehicle to control corresponding accessoriesof the vehicle. Each control interface includes one or more inputcontrols (“controls”) which an occupant manipulates to control anaccessory corresponding to the control interface. Each control interfacemay further include a display for displaying status information of anaccessory corresponding to the control interface.

For example, one control interface, referred to as the instrumentcluster, is behind the steering wheel for access by the driver of thevehicle. Another control interface, referred to as the center stackconsole, is between the driver and front passenger seats for access byboth of the driver and the front passenger. Other areas of a vehiclehaving control interfaces include door armrests where window, mirror,and security controls are placed and overhead consoles where sunroof andinterior lighting controls are placed.

A control interface such as the center stack console includes controlsand a display which are associated with multiple accessories such asaudio, navigation, and HVAC (heating, ventilating, and air conditioning)accessories. The surface of the control interface is divided intoadjacent areas each being associated with an accessory. Each area of thecontrol interface has controls positioned adjacent to a portion of thedisplay. The controls are typically implemented as mechanical switchessuch as pushbutton switches, rockers, slide switches, and rotaryswitches which an operator uses to control various functions of thecorresponding accessories.

Mechanical switches use a mechanical means to complete electricalcontact. As a result, mechanical switches are prone to failure as theiractivation causes mechanical wear on their moving components andelectrical contacts. Switch reliability declines and contactintermittent frequency increases over continued use. Repeated physicalcontact leads to deterioration of switch face legends and graphics.Mechanical switches are susceptible to contamination from externalmatter like dirt, food, and liquids. Ultimately, mechanical switches areexpensive for automotive use. In today's automobile, mechanical switchesas the controls of vehicle accessory control interfaces are responsiblefor some $400 or so of the automobile cost. As a result, automobiles areplagued by the problems associated with mechanical switches.

Besides their inherent physical drawbacks and cost, mechanical switchespresent opposition to automotive ergonomics by limiting vehicle stylingand layout options. As part of a control interface for a vehicleaccessory, mechanical switches are permanently fixed, numerous, andoccupy significant large portions of the surface of the controlinterface. For example, a standard HVAC system requires controls foradjusting vent selection, blower motor speed, temperature, etc. Thecontrols may be doubled to accommodate individual comfort controlbetween the driver and a passenger. In a luxury class vehicle, the HVACsystem may further require controls for heated mirrors, heated seats,rear passenger air flow, etc.

As vehicle accessories are augmented with additional features, thecontrol interfaces for these accessories become increasingly complex.This is because additional accessory features create demand for morecontrols to accommodate operator control of the additional features.Adding mechanical switches increases the size of the control interface.If the control interface has a display associated with the accessory,then this may require expansion of the control interface to accommodateoperator control of the additional features. Together the mechanicalswitches and the displays of a control interface consume valuable spaceof the surface of the control interface and increase overall cost.

Mechanical switches making up the controls of a control interfaceassociated with an accessory must be arranged in a fashion that iscomprehensive and intuitive to the operator. An excessive number ofbuttons or knobs clutters the control interface forcing the operator tohunt for desired switches. Sophisticated multi-function control knobs,those with switches that activate by tilting, pivoting, or swiveling,are obscure and difficult to maneuver for some operators. Furthermore,sophisticated control knobs have many intricate parts making themexpensive and prone to failure.

For a vehicle accessory associated with a control interface, uniquedesign consideration must be given to the control interface. The controlinterface must be accessible and convenient to operate and be visuallyappealing and demonstrate regard for operator safety.

SUMMARY OF THE INVENTION

The present invention is directed to the implementation of capacitivetouch switches in place of mechanical switches for the input controls ofcontrol interfaces associated with accessories of a vehicle.

Capacitive touch switches, referred to as touch pads, are a practicalsolution to the problems associated with mechanical switches. Capacitivetouch switches have a solid-state design that outlasts the lifetime ofmechanical switches. Capacitive touch switches may operate from behindthe surface of relatively thick non-conductive materials such as glassand are thus unaffected by external contamination. This characteristicgives automotive designers the option to implement control interfaceshaving large touch surfaces with customized exterior finishes thatenhance the appearance of the surfaces of the control interfaces.Capacitive touch switches can be constructed thin and flexible therebybeing able to follow complex contours of automobile surfaces. Thisprovides designers the freedom to locate control interfaces ontosurfaces not suitable for mechanical switches. Capacitive touch switchescan be constructed to be optically transparent thereby allowing thecontrols of a control interface to overlay a display of the controlinterface. This concept of overlapping controls onto a display of acontrol interface reduces the surface of the control interface.Furthermore, when fashioned this way, the display can produce directvisual feedback of touch switch activation. This creates an instinctiveergonomic solution to vehicle-operator interfacing. Capacitive touchswitches can be arranged to create custom control interfaces that canimitate anything from single button switch inputs to advancedtwo-dimensional touch arrays for recognizing multipoint inputs.

The expanding market of personal electronic devices with their remotewireless access and communications capabilities enables vehicles to haveaccessories that can be accessed remotely. Capacitive touch switches arereadily implemented into portable communications devices like cellphones, personal audio/video players, personal digital assistants, andhandheld computers. These devices can be used to wirelessly communicatewith vehicle control systems to give operators remote control overvehicle accessories.

It is an object of the present invention to provide a control interfacebetween a vehicle occupant and a vehicle for enabling the occupant tocontrol an accessory of the vehicle in which the control interfaceallows for enhanced placement and styling of input controls on thesurface of the control interface to create enhanced operator interactionwith the control interface.

It is another object of the present invention to provide a vehicleaccessory control interface having, as input controls, solid stateswitches based on capacitive touch technology in place of mechanicalswitches thereby improving switch reliability and lifetime and thuscreating a cost savings for the vehicle manufacturer and customer.

It is another object of the present invention to provide a vehicleaccessory control interface which operates on the principles of mutualcapacitance sensing to achieve single point and multipoint sensing ofhuman touch through relatively thick non-conductive surfaces. Anadvantage of mutual capacitance sensing over projected capacitancesensing is the ability to sense through thick surfaces including anycombination of natural or synthetic material such as glass, plastic,wood, rubber, and leather up to one quarter inch thick.

It is another object of the present invention to provide a vehicleaccessory control interface having single and multiple sensing regions(e.g., capacitive touch switches, touch pads) located at desired touchpoints on the surface of the control interface. The touch pads areplaced on the surface of the control interface such as to create uniquesurface locations that when touched generate single point, multipoint,or two-dimensional coordinate information identifying the touchedlocations.

It is another object of the present invention to provide a vehicleaccessory control interface having capacitive touch switches (touchpads) applied to the surface of the control interface laying directlyover a display of the control interface using highly conductive,optically transparent materials like Indium Tin Oxide (ITO), clearconductive polymers, or other such material. In this configuration, theITO is either applied directly to the surface of the control interfaceto create the desired touch switches or applied to a substrate filmlayer such as polyester which is then affixed to the surface of thecontrol interface. Touch pads can be constructed on single or multiplesubstrate layers to achieve desired layout and performancecharacteristics. For applications not requiring optically clear controlsurfaces, ITO can be substituted with a conventional material like metalfoil, conductive ink, metal film, or conductive epoxy.

It is another object of the present invention to provide a vehicleaccessory control interface having capacitive touch switches interfacedto display devices to create visual feedback when touch occurs. Thisfunctionality is similar to that of standard touch screens. However, thepresent invention builds upon specific touch screen technology withtouch screens that operate on the principles of mutual capacitancetechnology. In doing so, touch pads can be placed on the internal sideof a display surface. Using mutual capacitance technology, touch padscan be located behind thicker display surfaces like glass and still becapable of multi-touch point recognition. Likewise, sensitivitythresholds for touch pads can be increased to detect the presence of atouch prior to the touch actually touching the surface of the controlinterface. This proximity detection capability permits displays toremain inactive, dimmed, or hidden until an approaching object such as ahuman finger is sensed. When the object is sensed, the display brightensor becomes active just prior to the object making touched contact.

It is another object of the present invention to provide a vehicleaccessory control interface in which multiple vehicle accessories shareelectrical interface hardware and input controls of the controlinterface. By establishing common controls and displays of a controlinterface, monitoring and control of multiple vehicle accessories canoccur in the same area of a vehicle like an instrument cluster or centerstack console.

It is another object of the present invention to provide a vehicleaccessory control interface having capacitive touch switches which canbe arranged in various configurations. Based on sensing principles ofmutual capacitance, the capacitive touch switches can be located behind,in front of, or within the surface of the control interface. Likewise,the capacitive touch switches can be tailored to follow intricatecontours of the surface of the control interface and thus be madetransparent for placement directly in front of a display of the controlinterface.

It is another object of the present invention to provide a vehicleaccessory control interface having capacitive touch switches whichoperate based on the sensing principles of mutual capacitance in orderto recognize inputs such as single point, multipoint simultaneous,multipoint sequential, and multipoint gestural commands occurring byproximity or touch. Using multiple touch switch inputs, gesturing on thecontrol interface can be processed into operator input commands.Multiple gesture interpretation can be recognized and processed tocreate consecutive or simultaneous macro command sequences forcontrolling vehicle accessories.

It is another object of the present invention to provide a vehicleaccessory control interface capable of personalized and restrictedoperator access. By placing a conductor in the operator's seat anelectrical signal can be applied to the conductor to act as a carrier orsignature signal that is then sensed by the control interface duringtouch. The control interface can determine whether the source of theinput request is coming from the driver or a passenger. The request isallowed or restricted depending on the operator's usage rights.

It is another object of the present invention to provide a means ofachieving remote access and control over vehicle accessories. Byextending the use of capacitive touch switches to portable handheldelectronics operable for wireless communications, remote access tovehicle accessories is possible. An operator can remotely interface withvehicle accessories to control and monitor their status.

In carrying out the above objects and other objects, the presentinvention provides a system for enabling an operator to control anaccessory of a vehicle. The system includes a control interface and aprocessor. The control interface has a display surface and a touch areadefined by an electrically conductive layer adjacent to a portion of thedisplay surface. The conductive layer capacitively couples to anelectrically conductive object upon the conductive object touching thetouch area while the conductive layer is driven with an electricalcharge. The processor is operable for driving the conductive layer withthe electrical charge, detecting the capacitive coupling of theconductive layer to the conductive object upon the conductive objecttouching the touch area while the conductive layer is driven with theelectrical charge, generating a signal indicative of the conductiveobject touching the touch area upon detecting the capacitive coupling ofthe conductive layer to the conductive object, and providing the signalto an accessory of a vehicle for controlling the accessory as a functionof the conductive object touching the touch area.

Embodiments of the present invention provide an automotive-humaninterface system having a vehicle accessory control interface within anautomotive surface and provided with a display surface and capacitivetouch switches as input controls. The system further includes electronicdrive circuitry and electronic touch detection circuitry. The capacitivetouch switches are positioned in front of, within, or behind the displaysurface to detect the presence of human touch on the display surface andto detect and process motion gestures as specific input commands. Thedisplay surface may be anything from transparent to opaque material thatcan render changes to graphics or lighting to communicate visualacknowledgment of display surface touch. Haptic and audio feedbackcircuitry can provide an alternate or more comprehensive means ofsurface contact acknowledgment. The capacitive touch switches may befurther sensitized to recognize human proximity without completingsurface contact. Recognition of human presence before physical contactcan be used to produce a response prior to actual touching of thedisplay surface.

Embodiments of the present invention also provide a vehicle accessorycontrol interface having input controls and one or more displays inwhich the control interface improves human interaction with the controlsby centralizing active controls and hiding secondary controls that areless important or not required. Likewise, the accessibility to thecontrols is improved when the controls and a display are shared bymultiple vehicle accessories. The opportunity to rearrange or blockaccessory controls and manipulate visual display information on vehiclecontrol surfaces ultimately eliminates the design restrictions ofconventional automotive control interface design. Combining vehicleinterior design with the technology to process human gesturing as ameans of vehicle accessory control stimulates the human experience.

The above features, and other features and advantages of the presentinvention are readily apparent from the following detailed descriptionsthereof when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of a system having a vehicleaccessory control interface in accordance with an embodiment of thepresent invention;

FIG. 2 a illustrates a mounting configuration of capacitive touchswitches to the surface of a vehicle accessory control interface inaccordance with an embodiment of the present invention;

FIG. 2 b illustrates another mounting configuration of capacitive touchswitches to the surface of a vehicle accessory control interface inaccordance with an embodiment of the present invention;

FIG. 2 c illustrates another mounting configuration of capacitive touchswitches to the surface of a vehicle accessory control interface inaccordance with an embodiment of the present invention;

FIG. 2 d illustrates another mounting configuration of capacitive touchswitches to the surface of a vehicle accessory control interface inaccordance with an embodiment of the present invention;

FIG. 2 e illustrates another mounting configuration of capacitive touchswitches to the surface of a vehicle accessory control interface inaccordance with an embodiment of the present invention;

FIG. 2 f illustrates another mounting configuration of capacitive touchswitches to the surface of a vehicle accessory control interface inaccordance with an embodiment of the present invention;

FIG. 3 illustrates a vehicle accessory control interface havingcapacitive touch switches arranged in an exemplary configuration inaccordance with an embodiment of the present invention;

FIG. 4 illustrates a set of the capacitive touch switches of the vehicleaccessory control interface shown in FIG. 3 arranged in an exemplaryconfiguration for entering single input commands;

FIG. 5 illustrates another set of the capacitive touch switches of thevehicle accessory control interface shown in FIG. 3 arranged in anexemplary configuration for entering multiple sequential input commands;

FIG. 6 illustrates another set of the capacitive touch switches of thevehicle accessory control interface shown in FIG. 3 arranged in anexemplary configuration for entering single input commands and multiplesequential input commands;

FIG. 7 illustrates another set of the capacitive touch switches of thevehicle accessory control interface shown in FIG. 3 arranged in anexemplary configuration for entering single input and multiplesequential input commands using a two-dimensional input array;

FIG. 8 illustrates a detailed view of a portion of the two-dimensionalinput array shown in FIG. 7; and

FIG. 9 illustrates an electrical circuit diagram of the capacitive touchelectronics of a vehicle accessory control interface for readingmultiple touch switch inputs into a one input touch switch drive anddetection circuit in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Technology improvements and consumer appetite for more sophisticatedvehicles stimulates automotive manufactures into developing feature richaccessories while expanding their list of vehicle options. With theincrease in vehicle accessories and options, vehicle accessory controlinterfaces are more burdened than ever by the expanding size andcomplexity of accessory input controls. Successful management of thesurfaces of vehicle accessory control interfaces requires a new lookinto how their input controls are presented to the operator.

Capacitive touch switches offer a solution to the reliability and costconcerns associated with mechanical switches commonly used as the inputcontrols of vehicle accessory control interfaces. Capacitive touchswitches can solve issues relating to control interface complexity andergonomics that plague automotive interior designs.

Referring now to FIG. 1, a block diagram of a system 10 having a vehicleaccessory control interface 12 in accordance with an embodiment of thepresent invention is shown. Control interface 12 includes a surface 14.Control interface surface 14 is constructed from, for example, rigid,transparent, non-conductive material such as glass or plastic. Controlinterface 12 further includes one or more capacitive touch switches(i.e., touch pads) 16. Touch switches 16 are mounted either in front of,within, or behind control interface surface 14 at respective areas ofcontrol interface surface 14.

Control interface 12 is associated with one or more accessories of avehicle. To this end, control interface 12 is mounted in a surface ofthe vehicle at an area of the vehicle accessible by a vehicle operator24. Operator 24 can manipulate (i.e., directly touch or be in proximitywith) touch switches 16 (e.g., “controls”, “input controls”, “touchpads”) to control the functions of the vehicle accessories associatedwith control interface 12. Control interface surface 14 may function asa display which displays status of one or more of the vehicleaccessories associated with control interface 12. To this end, controlinterface surface 14 is a display surface.

System 10 further includes touch switch drive and detection electronics18. Drive and detection electronics 18 accompanies touch switches 16 todrive touch switches 16 with an electrical charge and to detect touchactivation of touch switches 16 while touch switches 16 are driven withthe electrical charge. Placement of drive and detection electronics 18can either be with touch switches 16 on control interface surface 14 orseparated from control interface 12 by an electrically conductive wire20 (as shown in FIG. 1). Drive and detection electronics 18 can beintegrated into a more elaborate control for increased functionality andreduced cost. While drive and detection electronics 18 drives touchswitches 16, drive and detection electronics 18 generates signalsindicative of activation of touch switches 16 in response tomanipulation (for example, touching) of touch switches 16 by operator24. A touch switch 16 while being driven with an electrical charge willactivate upon being contacted by a conductive object such as a humanfinger as a result of touch switch 16 capacitively coupling with theconductive object. Similarly, if sensitive enough, a touch switch 16while being driven with an electrical charge will activate upon aconductive object being in proximity with touch switch 16 as a result oftouch switch 16 capacitively coupling with the conductive object.

System 10 further includes accessory control electronics 22. Accessorycontrol electronics 22 is operable to control the functions of theaccessories associated with control interface 12 in accordance with theactivation of touch switches 16. To this end, accessory controlelectronics 22 receives the touch activation signals from drive anddetection electronics 18 over an electrically conductive wire 26. Inturn, accessory control electronics 22 controls the functions of theaccessories associated with control interface 12 in accordance with theactivation or control of touch switches 16.

Referring now to FIGS. 2 a through 2 f, with continual reference to FIG.1, different mounting configurations of capacitive touch switches 16 tocontrol interface surface 14 in accordance with embodiments of thepresent invention are shown. FIGS. 2 a through 2 f illustrate a partialcontrol interface 12 by showing only a handful of touch switches 16. Theactual number of touch switches 16 depends on requirements of thecomplete control interface 12. Depending on size and strengthrequirements of control interface 12, control interface surface 14 istypically between 0.100 to 0.250 inches in thickness and is made of amaterial such as glass or plastic.

In the mounting configuration of FIG. 2 a, touch switches 16 are locatedbetween the external side of control interface surface 14 and anon-conductive exterior layer 28. Layer 28 is placed as a protectiveshield to prevent direct operator contact to touch switches 16.Depending on how touch switches 16 are manufactured, layer 28 may alsorepresent the substrate onto which touch switches 16 are initiallyconstructed. Examples of this substrate are polycarbonate, acrylic, andpolyester. In any case, operator contact occurs on the outer surface 30of layer 28. Thickness of layer 28 is typically chosen at 0.005 to 0.015inches depending on design requirements. It is a characteristic of touchswitches 16 to exhibit increased signal strength as operator 24approaches to initiate contact. For this reason layer 28 is preferredthin when covering touch switches 16 that exhibit weak sensitivity andhence decreased signal strength. This is because thin layer 28compensates for weak touch switch signals by allowing operator 24 toobtain closer contact. Although it is not required that layer 28 be keptthin, this thickness presents a significant disadvantage in touchtechnologies different from that defined herein.

The mounting configuration in FIG. 2 b represents the simplest approachof placing touch switches 16 onto control interface surface 14. In thisconfiguration, touch switches 16 are placed directly onto the backside(i.e., internal side) of control interface surface 14 without aprotective layer against touch switches 16. This is a cost effectiveapproach provided that touch switches 16 do not require protection onthe back side of control interface surface 14. Placing touch switches 16onto the back side of control interface surface 14 clears external side32 of control interface surface 14 (i.e., the side of control interfacesurface 14 presented to operator 24) from touch switch components andprotective films. A designer is then free to transform external side 32of control interface surface 14 to create whatever appearance isdesired.

In the mounting configuration of FIG. 2 c, touch switches 16 are locatedbetween the internal side of control interface surface 14 and anon-conductive exterior layer 28. This construction is similar to thatfound in FIG. 2 a. Here layer 28 represents the substrate onto whichtouch switches 16 are initially constructed. Once assembled, layer 28can double as a protective shield for touch switches 16, thoughprotection may not be necessary as touch switches 16 are located on thebackside of control interface surface 14. Here again placing touchswitches 16 onto the internal side of control interface surface 14clears external side 32 of control interface surface 14 from touchswitch components and protective films. External side 32 of controlinterface surface 14 is then able to feature more appealing finishes.

In the mounting configuration of FIG. 2 d, a non-conductive layer 28 isplaced on the internal side of control interface surface 14 and touchswitches 16 are placed on layer 28. As a result, layer 28 is between theinternal side of control interface surface 14 and touch switches 16. Inthis configuration, layer 28 with touch switches 16 thereon can bebonded to the internal side of control interface surface 14 withoutexerting bonding stress on touch switches 16.

In the mounting configuration of FIG. 2 e, two separate touch switchlayers 16 a, 16 b are placed on respective sides of a non-conductivelayer 28 with the first touch switch layer 16 a being placed on theinternal side of control interface surface 14. This configuration isdesirable when two layers of touch switches 16 are necessary to meet thedesign requirements of control interface 12. A cost savings can berealized either in the manufacturing of touch switches 16 or bysimplifying assembly of control interface 12 when this configuration isselected.

In the mounting configuration of FIG. 2 f, two separate touch switchlayers 16 a, 16 b are placed on respective sides of a firstnon-conductive layer 28 a with the first touch switch layer 16 a beingplaced on the internal side of control interface surface 14 and a secondnon-conductive layer 28 b being placed over second touch switch layer 16b. Each layer of touch switches 16 is initially constructed as a singlelayer on separate substrates 28 a, 28 b. Once constructed, theindividual substrates 28 a, 28 b are then stacked to create a multiplelayer of touch switches 16.

Through rearrangement, substitution, or addition of the controlinterface components shown in FIG. 2 a though 2 f further variations ofcontrol interface 12 can be realized. For example, the configuration inFIG. 2 f can be characterized as having two single layer substrates 28a, 28 b. However, this configuration can also be characterized as havingone double layer substrate 28 a, as illustrated in FIG. 2 e, along withone exterior substrate layer 28 b as a form of protection. Likewise, theconfiguration in FIG. 2 e can be constructed with more than two touchswitch layers 16 a, 16 b. The touch switch layers 16 a, 16 b in FIG. 2 ecan be applied to external side 32 of control interface surface 14 tocreate multiple layer touch switches on external side 32 similar to theconfiguration in FIG. 2 a.

Referring now to FIG. 3, with continual reference to FIG. 1, a controlinterface 12 having capacitive touch switches 16 arranged in anexemplary configuration in accordance with an embodiment of the presentinvention is shown. Control interface surface 14 represents theaccessory control area of an automobile center stack console. Touchswitches 16 are spread out across control interface surface 14 toprovide operator 24 with the access to control vehicle accessories likeaudio, HVAC, and navigation. Touch switches 16 are arranged in separatetouch switch groups 40, 50, 60, and 70. As described in greater detailbelow with reference to FIGS. 4, 5, 6, and 7, touch switches 16 of eachtouch switch group are arranged in certain patterns and arrays.

In this example, touch switches 16 are shared among accessories toreduce the number of switches necessary for access to all availableaccessory functions. Likewise, control interface surface 14 is opticallytransparent for inclusion of a display device behind control interfacesurface 14. The display device can then project graphical images outwardthrough control interface surface 14 to assist operator 24 in locatingpositions of active touch switch 16 and to communicate the accessoryfunctions assigned to each touch switch 16. In this regard, controlinterface surface 14 is a display surface.

Referring now to FIG. 4, the arrangement of touch switches 16 of touchswitch group 40 of control interface 12 shown in FIG. 3 will bedescribed in greater detail. Touch switches 16 of touch switch group 40are arranged in a configuration for entering single input commands.Touch switches 16 of touch switch group 40 are suited for use asaccessory selection switches. Touch switch group 40, for instance,includes six touch switches 16. Each touch switch 16 can be assigned aprimary accessory function like audio, HVAC, navigation, communications,or vehicle status reporting. Once control of a particular accessory isinvoked, touch switch group 40 can modify its functionality to convertits touch switches 16 into secondary control touch switches that areexclusive to controlling the selected accessory.

Referring now to FIG. 5, the arrangement of touch switches 16 of touchswitch group 50 of control interface 12 shown in FIG. 3 will bedescribed in greater detail. Touch switches 16 of touch switch group 50are arranged in a configuration for entering multiple sequential inputcommands. To this end, touch switches 16 of touch switch group 50 arearranged close together in an arched layout. This layout is useful forcontrol interfacing imitating analog style control. Some examples of useare for adjusting temperature settings in an HVAC accessory; adjustingvolume, tone, or balance settings in an audio accessory; or as ascrubber bar for browsing information of a navigation accessory. Touchswitch group 50 includes, for instance, nine touch switches 16. However,switch detection electronics can process signal data from each of thesenine input controls (i.e., touch switches 16) to generate at leastseventeen distinct touch positions. Because of their close proximity toone another adjacent touch switches 16 can experience simultaneousactivation when operator 24 makes contact with control interface surface14. Adjacent touch switches 16 that experience simultaneous activationcan then be interpreted as input points falling between adjacent touchswitches 16. On the other hand, touch switch group 50 can be interpretedas fewer than nine touch switches 16 by either mapping switch inputs toa common command or ignoring activation of any number of the touchswitch signals to emulate a fewer number of touch switches 16.

Referring now to FIG. 6, the arrangement of touch switches 16 of touchswitch group 60 of control interface 12 shown in FIG. 3 will bedescribed in greater detail. Touch switches 16 of touch switch group 60are arranged in a configuration for entering single input commands andmultiple sequential input commands. To this end, touch switches 16 oftouch switch group 60 are arranged in respective arrays of single pointtouch switches 16. Each touch switch 16 can be activated to generate aspecific input command similar to that of a mechanical switch.Additionally, touch switches 16 are intentionally arranged in respectivearrays to accommodate touch input expressed in a gestural form.Activation of any one of touch switches 16 can prompt recognition of asingle point input command. However, if sequential activation of morethan one touch switch 16 should occur, then touch switch detectioncircuitry can perceive the touch sequence as an input gesture and notjust as a series of single point input commands.

An application of the arrays of touch switches 16 of touch switch group60 is for use as climate control adjustment in a vehicle. For example,tapping touch switch (touch pad) TP21 prompts a control to enter climateadjustment for the driver while tapping touch pad TP25 prompts climateadjustment for the passenger. After an occupant is selected, sequentialactivation of touch pads TP21-TP22-TP23-TP24-TP25 represents a commandto increase fan speed for the selected occupant. Conversely, sequentialactivation of these touch pads 16 in the reverse order represents acommand to reduce fan speed. At the same time, a sequential activationof touch pads TP16-TP17-TP19-TP23-TP27-TP29-TP30 represents the commandto decrease temperature for the selected occupant, while touch padactivation in the reverse order represents a command to increasetemperature.

Not all of touch switches 16 of a touch switch group need to beactivated for the gestural command to be recognized. Realistically, onlytwo touch switches 16 need to be activated sequentially for the commandto be recognized. If touch switches 16 are arranged close enough thentouch switch input signals can be processed to yield interpolated touchpositions between adjacent touch pads. In this way, a series of touchswitches 16 can be configured similarly to an analog control input suchas a potentiometer. This feature is useful when trying to create preciseset-point controls like temperature adjustment.

Referring now to FIG. 7, the arrangement of touch switches 16 of touchswitch group 70 of control interface 12 shown in FIG. 3 will bedescribed in greater detail. Touch switches 16 of touch switch group 70are arranged in a configuration for entering single input and multiplesequential input commands using a two-dimensional input array. As such,touch switches 16 are arranged in touch switch columns 16 a and touchswitch rows 16 b. Touch switch columns 16 a and rows 16 b are separatedfrom one another by a substrate layer 28 as detailed in FIGS. 2 e and 2f. The individual touch switch columns 16 a and rows 16 b called out inthe magnified view of FIG. 8 are formed by sequentially connected touchswitches 16. Each string of touch switches 16 making up a touch switchcolumn 16 a or row 16 b is positioned so as to minimize an overlap area72 common to both touch switch columns 16 a and rows 16 b. This is doneto reduce signal cross talk between touch switch columns 16 a and rows16 b. Additionally touch switches 16 may be slightly reduced in size toproduce areas void of touch pad material on both sides of substrate 28to further minimize overlap 72 and cross talk between touch switchlayers 16 a, 16 b.

When operator 24 touches control interface surface 14 the area ofcontact falls either on or near a touch switch column 16 a and row 16 b.The input signal read on each touch switch column 16 a and row 16 b thenrepresents the location where operator 24 is proximal to or touchingcontrol interface surface 14. If touch switch columns 16 a and rows 16 bare designed small enough then the operator contact area will includeboth a touch pad column 16 a and row 16 b. When contact is not directlyover a touch switch column 16 a or row 16 b then position isinterpolated by reading the input signal from the two closest touchswitch columns 16 a and rows 16 b. As all touch switch columns 16 a androws 16 b sense independently, it is possible to identify a multitude ofcontact areas within array 70. This characteristic makes array 70capable of simultaneous multi-point recognition. One or more touchlocations are then identified by the intersecting points of high signalstrength.

Because of their close proximity to one another, adjacent touch switchcolumns 16 a and rows 16 b can produce an input signal when operator 24makes contact between them on control interface surface 14. Adjacenttouch switch columns 16 a and rows 16 b experiencing simultaneous inputsignal can then be interpreted as input points that fall betweenadjacent touch switch columns 16 a or rows 16 b.

Technologies such as resistive touch screens are established as positionsensing touch panels. However, resistive touch screens do not completelyaddress the problems associated with mechanical switches. Resistivetouch screens must be placed on the external side of a control interfacesurface where they are continuously subjected to activation pressuresand must lay flat and have a simple footprint such as a square or arectangle. Their application is limited both by their geometry anddurability. Capacitive touch sensors (i.e., capacitive touch switches)are a better solution for applications that can benefit from interfacesurfaces with complex geometries. Likewise placement of capacitive touchsensors behind or within the control interface surface completely hidesthe electrical components to produce a clean and natural appearingsurface.

Referring now to FIG. 9, with continual reference to FIG. 1, anelectrical circuit diagram of the capacitive touch electronics ofcontrol interface 12 for reading multiple touch switch inputs 16 into aone input touch switch drive and detection circuit 18 in accordance withan embodiment of the present invention is shown. This electrical circuitdiagram illustrates exemplary electronic circuitry for operating amultitude of capacitive touch sensors 16 arranged as an array. Theoutlined circuitry block 18 represents a single input drive anddetection circuit for measuring the capacitive signal developed on atouch sensor 16.

In this example, switches A through H of a multiplexor 91 provide solidstate switching between touch sensors 16 and drive and detectionelectronics in a multiplexed fashion which permits one drive anddetection circuit 18 to sense input on eight independent touch sensors16. When solid state switch A of multiplexor 91 is closed, drive anddetection circuitry 18 becomes electrically connected to touch sensor 16b that is connected to ROW1. Drive and detection circuitry 18 turns eachsolid state switch 16 on in progression to read each of the four touchswitch columns 16 a and rows 16 b independently. This successivemultiplexed reading of touch inputs has the benefit of reducing thenumber of inputs and components required by drive and detection circuit18.

Drive and detection circuitry 18 demonstrates use of a microprocessor 92to control the multiplexing and sensor reading tasks. However, drive anddetection circuitry 18 could employ an ASIC or other such highlyintegrated circuit.

Position interpolation is possible by measuring capacitive signalstrength developed on adjacent touch switches 16, columns 16 a, and rows16 b and then interpolating actual touch position by comparing the readsignal strengths on two adjacent touch switch columns 16 a or rows 16 b.This effectively increases resolution without additional hardware.

The output response from drive and detection circuitry 18 can beindividual signals for each touch switch 16 or a serial data stream.They can represent an activated touch switch 16 or simply signalstrength on each touch switch 16 to be processed further by accessorycontrol electronics 22.

When reading a touch switch 16 the input signal acquired by drive anddetection circuitry 18 is a numerical value representing the amount ofelectrical charge developed on the touch switch as a result ofcapacitance coupling to its surroundings. For a single switch input thevalue of measured charge can be compared directly to a threshold valueto determine if activation of touch switch 16 has occurred. Anotherdetection method is to compare the value of measured charge against apreviously read value to determine if a change in signal has occurred.The measured value then represents an amount of change over time.

When sufficient signal is sensed on a touch switch array of controlinterface 12 and is detected by drive and detection circuitry 18 asmoving from one coordinate location to another in time, then thissequence of touch coordinates can be captured by drive and detectioncircuitry 18 and decoded as a gestural input command. Gestural commandinputs can be used to communicate special instructions by the operatorto the accessory control. For example a touch gesture tracing theoutline of a circle or partial arc on the touch switch array mayrepresent a command to rotate or turn a virtual control knob that isrepresented on a display behind control interface surface 14. Tracing anX on the touch switch array could signify the canceling of a functionwhile tracing a check mark might communicate acceptance or completion ofaccessory adjustments.

A unique characteristic of capacitive touch sensors 16 of controlinterface 12 is their ability to detect an approaching object before theobject makes contact with control interface surface 14. Thischaracteristic is useful when implementing wakeup response on a ‘dead’control interface 12. In doing so, control interface 12 can remaindarkened or inactive until operator 24 comes within range of controlinterface surface 14 at which time control interface 12 will acknowledgeoperator 24 by activating the display, lighting the control interfacepanel, sending an audible wake-up confirmation, or other such feedbackresponse to inform operator 24 that their presence or approach isrecognized.

There are at least four ways to perform the proximity detection functionof control interface 12 using capacitive touch switches 16. In a firstmethod, the sensitivity threshold used by drive and detectionelectronics 18 to determine activation of a touch switch 16 can belowered. This makes touch switches 16 more sensitive to approaching orproximal objects by reducing the amount of input signal that mustdevelop on a touch switch 16 before activation is declared by drive anddetection electronics 18. In a second method, proximity detection signalvalues are read from a multitude of touch switches 16 and mathematicallysummed by drive and detection electronics 18. This creates a collectivesignal value having a greater magnitude of change in response to anobject approaching or proximal to control interface surface 14. In athird method, a multitude of touch switches 16 are connected together tocreate a touch switch 16 having greater surface area. This isaccomplished by turning on two or more of touch switches 16 inmultiplexor 91 to electrically join individual touch switches 16together. By increasing switch surface area the signal input of driveand detection electronics 18 will develop greater signal change toapproaching or proximal objects. This effectively makes the touch switchsurface more sensitive. In a fourth method, control interface 12 hasdedicated touch sensor areas or regions about control interface surface14 having characteristically high sensitivity for detecting approachingor proximal objects. These touch sensor areas can be placed adjacent toor intermixed among touch switches 16. Likewise, the touch sensor areascan be placed on separate conductive layers.

Any combination of the four noted proximity detection methods can beimplemented to achieve the desired characteristics of proximitydetection to an approaching or proximal object. Proximity detection canbe implemented across the touch interface surface or selectivelycontrolled by sensing the capacitive signal on desired touch switches 16and touch areas.

With proximity detection, gestural commands can be captured andprocessed in a three dimensional form. The variations in touch switchsignal strength along with touch switch location and signal timetracking provide a three dimensional gesturing palette on controlinterface surface 14. Recognition of hand gesturing above controlinterface surface 14 now takes on a third component of depth or distanceas processed by touch switches 16 as signal strength. In this way,proximity detection is suited for advanced gesture recognition byprocessing not only multipoint and sequential point gestures in the timedomain but also adding a third component of depth that can be translatedfor true gestural input.

Another method of vehicle accessory control utilizes portable handheldelectronic devices with wireless communications capability. Such devicesinclude cell phones, PDAs, laptops, and netbook computers and can beused to remotely interface with and gain access to vehicle accessories.Using wireless communications standards like WiFi, Bluetooth, 3G, andZigBee, an operator 24 can remotely access a vehicle and itsaccessories. Vehicle accessories equipped with wireless communicationsor linked on internal networks to devices having wireless communicationscapability give operator 24 a wireless access point to communicate withthe vehicle. In doing such, operator 24 can receive real time vehiclestatus while away from the vehicle. Likewise, operator 24 can controlvehicle accessories from personal electronic devices without having tobe near their vehicle. Remote communications with the vehicle allowsoperator 24 to monitor vehicle security status. Vehicle accessories likeHVAC, sunroof, and window lift controls can be accessed to adjustvehicle ventilation and temperature characteristics. Personal electronicdevices can connect with vehicle accessories like audio head units andvideo players to share AV files and information. Likewise, wirelessportable devices can link with vehicle electronics to exchangeinformation like contact lists, appointments, notes, etc.

While embodiments of the present invention have been illustrated anddescribed, it is not intended that these embodiments illustrate anddescribe all possible forms of the present invention. Rather, the wordsused in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the present invention.

What is claimed is:
 1. A system for enabling an operator to control anaccessory of a vehicle, the system comprising: a control interfaceincluding a display panel and a processor associated with the displaypanel; the display panel including a touch surface, an electricallynon-conductive support adjacent the touch surface, a plurality of touchareas, each of the touch areas being defined by a single electricallyconductive pad situated between the support and a portion of the touchsurface, wherein the conductive pads individually capacitively couple toan electrically conductive object upon the conductive object moving intoclose proximity to the touch area while the conductive pad is drivenwith an electrical charge; the processor being operative in a first modein which the processor detects the capacitive coupling of the conductivepad to the electrically conductive object, generates a signal indicativeof the capacitive coupling, and provides the signal to an accessory of avehicle for controlling the accessory based on the capacitive coupling;the processor being operative in a second mode in which the processordetects capacitive coupling of a plurality of the conductive pads to anelectrically conductive object, recognizes a pattern or sequence of thecoupling of the plurality of the conductive pads, and generates a firstcontrol signal indicating a first adjustment to a feature of at leastone of the vehicle accessories when the pattern or sequence has a firstdirection, or generates a second control signal indicating a secondadjustment to the feature of the at least one vehicle accessory when thepattern or sequence has a second direction, wherein the first directionis opposite the second direction and the first adjustment is oppositethe second adjustment; the processor being operative in a third mode inwhich the processor remotely communicates with a wireless electronicdevice, using a transceiver, associated with the processor, and controlsat least one of the vehicle accessories in accordance with an outputcommand received from the wireless electronic device.
 2. The system ofclaim 1, wherein at least one of the display panel and the conductivepad is optically transparent.
 3. The system of claim 1, wherein theconductive pad is optically transparent and comprises one of Indium TinOxide and a clear conductive polymer.
 4. The system of claim 1, whereinthe touch surface acts as a support for attachment of the conductive padto the portion of the display panel.
 5. The system of claim 1, whereinthe conductive pad is situated between the support and a portion of aninternal side of the touch surface facing opposite an external side thatis accessible for being approached by the conductive object.
 6. Thesystem of claim 1, wherein the display panel comprises a non-conductivematerial and includes at least one of glass and plastic.
 7. The systemof claim 1, wherein the display panel has a non-planar contour and theconductive layer has a contour corresponding to the non-planar contourof the display panel.
 8. The system of claim 1, wherein each of theconductive pads is isolated from the other by an electricallynon-conductive substrate.
 9. The system of claim 8, wherein each of thesingle electrically conductive pads comprises only a single electrode.10. The system of claim 8, wherein the processor transmits informationindicative of the status of at least one of the control interface andthe accessory to the wireless electronic device.
 11. The system of claim8, wherein the processor exchanges data between the control interfaceand the wireless electronic device.
 12. The system of claim 1, whereinthe processor is configured to: detect the amount of capacitive couplingof the conductive pad to the conductive object, and generate a signalindicative of the amount of capacitive coupling; and wherein theprocessor includes a microprocessor for receiving the signal indicativeof the amount of capacitive coupling, the microprocessor providing anoutput command based on the amount of capacitive coupling to theaccessory of the vehicle for controlling the accessory based on theamount of capacitive coupling of the conductive pad to the conductiveobject.
 13. The system of claim 12, wherein the microprocessordetermines the output command in response to a single point touch inputof the conductive object on the touch area.
 14. The system of claim 12,wherein the microprocessor determines the output command in response toa multipoint touch input of the conductive object on the touch area. 15.The system of claim 12, wherein the microprocessor determines the outputcommand in response to sequential single point touch inputs of theconductive object on the touch area.
 16. The system of claim 12, whereinthe microprocessor determines the output command in response tosequential multipoint touch inputs of the conductive object on the toucharea.
 17. The system of claim 12, wherein the microprocessor determinesthe output command in response to a single point proximity input of theconductive object to the touch area prior to the conductive objecttouching the touch area.
 18. The system of claim 12, wherein themicroprocessor determines the output command in response to a multipointproximity input of the conductive object to the touch area prior to theconductive object touching the touch area.
 19. The system of claim 12,wherein the microprocessor determines the output command in response tosequential single point proximity inputs of the conductive object to thetouch area prior to the conductive object touching the touching area.20. The system of claim 12, wherein the microprocessor determines theoutput command in response to sequential multipoint proximity inputs ofthe conductive object to the touch area prior to the conductive objecttouching the touch area.
 21. The system of claim 12 wherein a responseof the accessory to the output command comprises at least one of audiofeedback and haptic feedback.
 22. The system of claim 12, wherein theprocessor achieves proximity detection of an electrically conductiveobject to the touch area by lowering a sensitivity threshold of theprocessor to make the touch area more sensitive to nearby electricallyconductive objects.
 23. The system of claim 12, wherein the processorachieves proximity detection of an electrically conductive object to thetouch area by reading capacitive coupling amounts at a plurality oftouch areas and summing the capacitive coupling amounts to produce asummed capacitive coupling amount.
 24. The system of claim 12, whereinthe control interface includes a plurality of other touch areas eachdefined by a single electrically conductive pad, wherein the processorachieves proximity detection of an electrically conductive object byelectrically connecting the touch area with at least one of the othertouch areas to make the touch area more sensitive to nearby electricallyconductive objects.
 25. The system of claim 12, wherein the processortransmits information indicative of the status of at least one of thecontrol interface and the accessory to the wireless electronic device.26. The system of claim 12, wherein the processor exchanges data betweenthe control interface and the wireless electronic device.
 27. The systemof claim 12, wherein the single electrically conductive pad comprisesonly a single electrode.
 28. The system of claim 1, wherein the singleelectrically conductive pad comprises only a single electrode.
 29. Thesystem of claim 1, wherein the processor transmits informationindicative of the status of at least one of the control interface andthe accessory to the wireless electronic device.
 30. The system of claim1, wherein the processor exchanges data between the control interfaceand the wireless electronic device.
 31. The system of claim 1, wherein aplurality of the touch areas are grouped together and arranged in anarched layout, wherein sequential capacitive coupling with at least someof the conductive pads of the grouped touch areas imitates and analogstyle control.